1. Field of the Invention
This invention relates to a stop device for use in apparatus for shearing wire, rod, or like elongate work into desired lengths, and more specifically to such a device for stopping the work as same is fed in its longitudinal direction before being cut off into a desired length. The shearing apparatus including the stop device in accordance with this invention is contemplated for use preferably in or with a header or machine which forms the heads of rivets, bolt blanks, screw blanks, and similar products, by upsetting the ends of the wire lengths, but with no unnecessary limitation thereto being intended.
2. Description of the Prior Art
In the stop device as heretofore constructed and used for the purpose under consideration, there has been provided a stop member which has a working surface formed at an angle to the plane normal to the predetermined direction in which wire or like work is fed. As the work is fed endwise into abutting contact with the working surface of the stop member, therefore, an unoccupied space is created therebetween which is intended to lessen the impact of shearing operation transmitted to the stop device.
The sloping stop surface of the prior art device, however, is incapable of effectively relieving the impact of shearing operation, so that the stop member and other parts of the device have been very liable to suffer damage or rapid aging by the repeated shearing operation. Furthermore, since the length into which the wire is cut off is determined by the distance between the stop member and the fixed shear element of the shearing apparatus, the sloping stop surface of the prior art device is easy to cause irregularity in the wire lengths produced.
A further objection to the prior art stop device concerns its mechanism for moving the stop member toward and away from the fixed shear element for adjustably varying the length into which wire is to be cut off. This mechanism, usually employing worm gearing, has been such that the stop device has been made unnecessarily complex in construction.